Countersinking-tool



G. R. EHLERS.

COUNTERSINKING TOOL. APPLICA-Hou FILED ocr. 2a, 1919.

Patented Dec. 14, 1920.

UNITED STATES PATENT oFEmE.

GEORGE R. EHLEBS, 0F WILMINGTON', DELAWARE, ASSIGNOB. T0 AUTOMATIC COUNTER SINKING TOOL COMPANY, A CORPORATION OF DELAWARE.

To all whom 'it may concern:

Be it known that I, GEORGE R. EHLERS, a citizen of the United States, residing .at Wilmington, in the county of New Castle and State of Delaware, have invented newand usefulv Improvements in Countersinking-Tools, of which the following is a speci cation..

This invention relates to improvements in tools for counter-sinking and aims to provide a tool whereby the operation of counter- 4sinking may be performed from the opposite or reverse side of the counter-sink.

This is lspecially desirable when the counter-sink is to be located upon the bottom face of the plate, or other piece of work, to avoid the employment "of two men for holding the operating tool, the present tool acting under pressure exerted from above to draw the counter-sinking'bit upward in a direction opposite to the direction of pressure and capable of being operated after the manner of an ordinary drill.l

Another object of the invention is the provision of a counter-sinkingA tool in which the cutting blades are normally housed within the shank of the tool to permit of theirbeing-inserted through an opening, the 0peration of resting thetool upon the work and exerting aninitial pressure thereon preparatory to countersinking, causing the blades to be forced outward for use.

Another object is the provision of :a counter-sinking tool of the above character, which is simple and durable in construction and which may be operated with a minimum amount of time and labor.

Other objects and advantages of the vihvention -will appear as' the following description is read in connection with the accompanying drawings, 1

ln the drawings p Figure 1 is a longitudinal sectional view through a tool showingthe parts in normal positions.

Fig. 2 is a view similar to Fig. 1, with the parts in position for use and the bit expanded. l

Fig. 3 is vafragmentary elevation of the upper end of 4thef'inner sleeve.v

Fig. 4 is a transverse sectional view on the line 4 4 of Fig. 2.

Fig. 5 is a similar view on the line 5-5 of the opposite end agalnst the upper end of rig. 2.

lSpe'cifumtion of Letters Patent. Patented Dec. 14;, 1920. Application mea october 2s. 1919. serial No. 334,028.

Fig. 6 is an enlarged fragmentary lon tudinal section through the lower end of t e inner sleeve and showing the lcutting blade or bit.

Fig. 7 is a transverse sectional view on the line 7-7 of Fig. 6. v

Referring to the -drawin in detail,

wherein' like characters of re erence denote vcorresponding parts, the tool comprises a body member, .which is preferably circular in cross section, being hollow and forming an outer sleeve 10. This sleeve carries a .reduced extension 11, which projects from one end and terminates in va shank 12 by means of which the tool is ysecured in a suitable operating member.

having their opposite ends reduced and threaded as indicated. at 18 and 19, the

former entering a threadedI socket 20 andv the latter receiving a cap 21, which holds the sections together. Extending upward throughthe inner sleeve 14 is a longitudinally slidable bit v expanding rod y22, the lower end of which is adapted to engage the inner ends of the cutting blades 23 and to force them outward beyond the periphery of theend of the sleeve 14, the said blades being urged inwardly within the periphery of the rsleeve by means of springs 24, one end of which enters a notch 25 formed in each of the blades 23 and the opposite end bears against a shoulder 26 formed in each of the sections 17. The opposite' end of the rod 22 is provided with a head, which operates within the bore 13.

Surrounding the inner sleeve 14 and slidably mounted within the sleeve 10, is an intermediate sleeve 28. A spring 29 located within the outer sleeve has one end b earlng against a shoulder 30 provided-therem and the intermediate sleeve 28 and nacts to .nor^

mally 'force thesleeves 10 and 28 outward with respect to one another. The lower or outer end of the sleeve 28 is provided with a flange 31 andA threadedly secured upon this flange is a collar 32, which serves to connect to the lower' end of the sleeve 28 a bearing member 33. Antifriction devices34 are lo-y dium of a screw'34, which enters the threaded opening provided in the outer sleeve 10 and has a reduced extremity engageable be-A neath thehead 27, the said extremity also being engageable with a longitudinally disposed slot 35 provided in the inner sleeve 14. The inner sleeve 14 is also connected to the head 27 through the medium of coil springs 36, which are locat d upon diametrically opposite sides of the said sleeve andl within -slots 37 provided in the said sleeve.

The intermediate sleeve 28 is slotted at fone end as indicated at 38 and rotatably mounted in this slot isa pinion 39, which is adapted to engage a rack 40 provided longitudinally of theinner sleeve 14 and a rack 41 provided upon the inner periphery of the outer-sleeve 10. i

The parts of the tool being in the position indicated in Fig. 1, the bit end of the tool is inserted through the opening to be countersunk. When pressure is applied to the tool, the end of the rod 22 will engage the ends of the cutting blades 23 and force the cutting edges outward tothe position shown in Fig.

2, whereupon further downward pressure exerted during the operation of the tool will cause the outer sleeve 10 to move downward and this downward movement will, through the engagement of the pinion 39 with the racks 40 and 41, cause Vthe inner sleeve 14 to move upward, the movement being regulated by the cutting of the bits or blades 23. After the counter-sinking operation has been com pleted, and pressure is relieved from the tool, Athe cutting blades will be automatically re- 'l What is claimed is tracted,`` whereupon the tool may be withdrawn from theopenings.

The invention is susceptible of various changes in its form, proportions and minor details of construction, and the right is herein reserved to make such changes as properly fall within'th'e scope of the appended claims.

1. A counter-sinking tool embodying a plurality of telescopic members, rack teeth carried by said members, an expansible bit projecting beyondconeNe/nd jheredfAandman pinion connecting the telescopic members, e5 wherebyl pressure exerted upon the tool in the direction of the bit will expand the same and move the bit in a direction opposite to the direction of pressure.

2. A counter-sinking tool comprising a1 70 body portion, having an attachingshank at' one end thereof, a sleeve movable longitudinally of the bodynportionand having anl expansible bit'located at the end opposite' theshank and projecting beyond the body portion, a rod extending through the sleeve and having one end engageable with the bit, spring actuated means for holding the bit against such expansion, and means .whereby pressure upon the body portion of the too'lso in a direction toward the bit willoperate the rod and expand the bit and act to move the said bit in a direction opposite tothe direc? tion of pressure upon the body portion.

3. A counter-sinking tool comprising a body portion having an attachingshank at one end thereof, a sleeve movable longitudinally ofthe body portion'and having an expansible bit located at the end opposite the shank and projecting beyond the body portion, a rod extending through the sleeve and having, one end engageable with the bit for holding the bit against such expansion, means whereby pressure upon the bodyportion of the tool will ,release the holding means and permit of the expansion of the bit and a pinion connecting the body portion and sleeve, whereby said pressure upon the body portion will also act tomove the ybit inwardly in a direction opposite to the direction of pressure.

kIn testimony whereof I aix my signature.

GEORGE-1R, EHLERS. 

